Pakistan will not go for another 4th generation fighter jet. We already have upgraded f16s and f16blocks 52s, Jf17 block 1,2 and latest jf17 block 3 next year, we also have heavily upgraded Mirage rose which will stay with us till 2035. Why would we spend billions in to another platform than spend all that money in to more f16s or jf17 block 3s and also in to 5th generation.
The downside is Chinese j31 fighter has been delayed till 2035. The Turkish tfx has the big question till 2030. But you never know J20 might be available to buy in the near future.